The present invention concerns a shaped mass based on collagen resorbable in the body, its preparation and its use in medicine, especially as surgical material and/or as an active material depot.
It is known to introduce into the body bioresorbable materials, such as collagen, in freeze-dried or foamed form and thus to fill up, e.g., bone or tissue defects. Such implants can be used to stop bleeding and can also be employed for the induction of granulation tissue; however, they have the disadvantage that they are relatively loosely constructed and, therefore, upon moisture take-up, lose their shape relatively quickly. Thus, the body tissues scarcely have time to grow again to a sufficient extent. Therefore, it is desirable to develop similar materials which display the advantages of the known collagen preparations, but simultaneously have a more stable consistency and, therefore, lose their shape less quickly.
It is also known that active materials, such as antibiotics, can be embedded in certain synthetic resins, such as, e.g., polymethacrylates and/or polyacrylates, and are slowly liberated from these non-resorbable carriers when they are used as implantations in the body. Such active material-containing synthetic resins are commercially available, e.g., as spheroids which are implanted near the bone or soft tissue infections to be treated and can provide a sufficiently high active material concentration in situ. This new therapy has proved to be useful in the case of various infections in the body, but has the disadvantage that, in certain cases, the spheroids cannot be left in the organism; on the contrary, after some time, they must be removed, which means a renewed surgical intervention and thus a renewed risk of infection. Therefore, it is also desirable to have an alternate therapeutic principle so that the mentioned removal of the spheroids can be obviated.
From Federal Republic of Germany Patent Specification No. 12 93 396 is also known the use of polyhydroxyacetic acid esters for the production of antibiotic-containing, resorbable surgical stitching materials, tubes and films. Furthermore, in published Federal Republic of Germany patent application No. 20 51 850, there are described pharmaceutical compositions which are characterized in that they contain an active material in combination with a polylactide or a copolymer of lactide and glycolide units.